/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.tree.analysis;

import java.util.List;

import org.objectweb.asm.Handle;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.IntInsnNode;
import org.objectweb.asm.tree.InvokeDynamicInsnNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MultiANewArrayInsnNode;
import org.objectweb.asm.tree.TypeInsnNode;

/**
 * An {@link Interpreter} for {@link BasicValue} values.
 * 
 * @author Eric Bruneton
 * @author Bing Ran
 */
public class BasicInterpreter extends Interpreter<BasicValue> implements Opcodes {

  public BasicInterpreter() {
    super(ASM6);
  }

  protected BasicInterpreter(final int api) {
    super(api);
  }

  @Override
  public BasicValue newValue(final Type type) {
    if (type == null) {
      return BasicValue.UNINITIALIZED_VALUE;
    }
    switch (type.getSort()) {
    case Type.VOID:
      return null;
    case Type.BOOLEAN:
    case Type.CHAR:
    case Type.BYTE:
    case Type.SHORT:
    case Type.INT:
      return BasicValue.INT_VALUE;
    case Type.FLOAT:
      return BasicValue.FLOAT_VALUE;
    case Type.LONG:
      return BasicValue.LONG_VALUE;
    case Type.DOUBLE:
      return BasicValue.DOUBLE_VALUE;
    case Type.ARRAY:
    case Type.OBJECT:
      return BasicValue.REFERENCE_VALUE;
    default:
      throw new Error("Internal error");
    }
  }

  @Override
  public BasicValue newOperation(final AbstractInsnNode insn) throws AnalyzerException {
    switch (insn.getOpcode()) {
    case ACONST_NULL:
      return newValue(Type.getObjectType("null"));
    case ICONST_M1:
    case ICONST_0:
    case ICONST_1:
    case ICONST_2:
    case ICONST_3:
    case ICONST_4:
    case ICONST_5:
      return BasicValue.INT_VALUE;
    case LCONST_0:
    case LCONST_1:
      return BasicValue.LONG_VALUE;
    case FCONST_0:
    case FCONST_1:
    case FCONST_2:
      return BasicValue.FLOAT_VALUE;
    case DCONST_0:
    case DCONST_1:
      return BasicValue.DOUBLE_VALUE;
    case BIPUSH:
    case SIPUSH:
      return BasicValue.INT_VALUE;
    case LDC:
      Object cst = ((LdcInsnNode) insn).cst;
      if (cst instanceof Integer) {
        return BasicValue.INT_VALUE;
      } else if (cst instanceof Float) {
        return BasicValue.FLOAT_VALUE;
      } else if (cst instanceof Long) {
        return BasicValue.LONG_VALUE;
      } else if (cst instanceof Double) {
        return BasicValue.DOUBLE_VALUE;
      } else if (cst instanceof String) {
        return newValue(Type.getObjectType("java/lang/String"));
      } else if (cst instanceof Type) {
        int sort = ((Type) cst).getSort();
        if (sort == Type.OBJECT || sort == Type.ARRAY) {
          return newValue(Type.getObjectType("java/lang/Class"));
        } else if (sort == Type.METHOD) {
          return newValue(Type.getObjectType("java/lang/invoke/MethodType"));
        } else {
          throw new IllegalArgumentException("Illegal LDC constant " + cst);
        }
      } else if (cst instanceof Handle) {
        return newValue(Type.getObjectType("java/lang/invoke/MethodHandle"));
      } else {
        throw new IllegalArgumentException("Illegal LDC constant " + cst);
      }
    case JSR:
      return BasicValue.RETURNADDRESS_VALUE;
    case GETSTATIC:
      return newValue(Type.getType(((FieldInsnNode) insn).desc));
    case NEW:
      return newValue(Type.getObjectType(((TypeInsnNode) insn).desc));
    default:
      throw new Error("Internal error.");
    }
  }

  @Override
  public BasicValue copyOperation(final AbstractInsnNode insn, final BasicValue value) throws AnalyzerException {
    return value;
  }

  @Override
  public BasicValue unaryOperation(final AbstractInsnNode insn, final BasicValue value) throws AnalyzerException {
    switch (insn.getOpcode()) {
    case INEG:
    case IINC:
    case L2I:
    case F2I:
    case D2I:
    case I2B:
    case I2C:
    case I2S:
      return BasicValue.INT_VALUE;
    case FNEG:
    case I2F:
    case L2F:
    case D2F:
      return BasicValue.FLOAT_VALUE;
    case LNEG:
    case I2L:
    case F2L:
    case D2L:
      return BasicValue.LONG_VALUE;
    case DNEG:
    case I2D:
    case L2D:
    case F2D:
      return BasicValue.DOUBLE_VALUE;
    case IFEQ:
    case IFNE:
    case IFLT:
    case IFGE:
    case IFGT:
    case IFLE:
    case TABLESWITCH:
    case LOOKUPSWITCH:
    case IRETURN:
    case LRETURN:
    case FRETURN:
    case DRETURN:
    case ARETURN:
    case PUTSTATIC:
      return null;
    case GETFIELD:
      return newValue(Type.getType(((FieldInsnNode) insn).desc));
    case NEWARRAY:
      switch (((IntInsnNode) insn).operand) {
      case T_BOOLEAN:
        return newValue(Type.getType("[Z"));
      case T_CHAR:
        return newValue(Type.getType("[C"));
      case T_BYTE:
        return newValue(Type.getType("[B"));
      case T_SHORT:
        return newValue(Type.getType("[S"));
      case T_INT:
        return newValue(Type.getType("[I"));
      case T_FLOAT:
        return newValue(Type.getType("[F"));
      case T_DOUBLE:
        return newValue(Type.getType("[D"));
      case T_LONG:
        return newValue(Type.getType("[J"));
      default:
        throw new AnalyzerException(insn, "Invalid array type");
      }
    case ANEWARRAY:
      String desc = ((TypeInsnNode) insn).desc;
      return newValue(Type.getType("[" + Type.getObjectType(desc)));
    case ARRAYLENGTH:
      return BasicValue.INT_VALUE;
    case ATHROW:
      return null;
    case CHECKCAST:
      desc = ((TypeInsnNode) insn).desc;
      return newValue(Type.getObjectType(desc));
    case INSTANCEOF:
      return BasicValue.INT_VALUE;
    case MONITORENTER:
    case MONITOREXIT:
    case IFNULL:
    case IFNONNULL:
      return null;
    default:
      throw new Error("Internal error.");
    }
  }

  @Override
  public BasicValue binaryOperation(final AbstractInsnNode insn, final BasicValue value1, final BasicValue value2) throws AnalyzerException {
    switch (insn.getOpcode()) {
    case IALOAD:
    case BALOAD:
    case CALOAD:
    case SALOAD:
    case IADD:
    case ISUB:
    case IMUL:
    case IDIV:
    case IREM:
    case ISHL:
    case ISHR:
    case IUSHR:
    case IAND:
    case IOR:
    case IXOR:
      return BasicValue.INT_VALUE;
    case FALOAD:
    case FADD:
    case FSUB:
    case FMUL:
    case FDIV:
    case FREM:
      return BasicValue.FLOAT_VALUE;
    case LALOAD:
    case LADD:
    case LSUB:
    case LMUL:
    case LDIV:
    case LREM:
    case LSHL:
    case LSHR:
    case LUSHR:
    case LAND:
    case LOR:
    case LXOR:
      return BasicValue.LONG_VALUE;
    case DALOAD:
    case DADD:
    case DSUB:
    case DMUL:
    case DDIV:
    case DREM:
      return BasicValue.DOUBLE_VALUE;
    case AALOAD:
      return BasicValue.REFERENCE_VALUE;
    case LCMP:
    case FCMPL:
    case FCMPG:
    case DCMPL:
    case DCMPG:
      return BasicValue.INT_VALUE;
    case IF_ICMPEQ:
    case IF_ICMPNE:
    case IF_ICMPLT:
    case IF_ICMPGE:
    case IF_ICMPGT:
    case IF_ICMPLE:
    case IF_ACMPEQ:
    case IF_ACMPNE:
    case PUTFIELD:
      return null;
    default:
      throw new Error("Internal error.");
    }
  }

  @Override
  public BasicValue ternaryOperation(final AbstractInsnNode insn, final BasicValue value1, final BasicValue value2, final BasicValue value3)
      throws AnalyzerException {
    return null;
  }

  @Override
  public BasicValue naryOperation(final AbstractInsnNode insn, final List<? extends BasicValue> values) throws AnalyzerException {
    int opcode = insn.getOpcode();
    if (opcode == MULTIANEWARRAY) {
      return newValue(Type.getType(((MultiANewArrayInsnNode) insn).desc));
    } else if (opcode == INVOKEDYNAMIC) {
      return newValue(Type.getReturnType(((InvokeDynamicInsnNode) insn).desc));
    } else {
      return newValue(Type.getReturnType(((MethodInsnNode) insn).desc));
    }
  }

  @Override
  public void returnOperation(final AbstractInsnNode insn, final BasicValue value, final BasicValue expected) throws AnalyzerException {
  }

  @Override
  public BasicValue merge(final BasicValue v, final BasicValue w) {
    if (!v.equals(w)) {
      return BasicValue.UNINITIALIZED_VALUE;
    }
    return v;
  }
}
